Pub Date : 2020-07-22DOI: 10.4236/ojce.2020.103018
Mouhamed Lamine Chérif Aidara, Makhaly Bâ, A. Carter
The most famous model known in prediction of dynamic modulus for asphalt concretes is the Witczak and Hirsh models. These models didn’t use the mineralogical and chemical properties of aggregates. Witczak models used the passing or refusal percentage to sieve diameters and Hirsh model used the volumetric analysis. All models developed until now considered that the aggregates were geotechnical conforming to standards. In this study the first mineralogical and chemical properties were considered through the percentage of silica in the rock source of aggregates and the electric aggregate particles charge zeta. Dynamic modulus values used for regression process are determined from complex modulus test on nine asphalt concretes mix designed with aggregate types (basalt of Diack, quartzite of Bakel and Limestone of Bandia). Between Twelve initial inputs, the statistical regression by exclusion process keeps only seven parameters as input for the model. The mineralogical model showed good accuracy with R2 equal to 0.09. The student test on the model parameters showed that all the parameters included in the model were meaningful with good p inferior to 0.05. The Fisher test on the model showed the same result. The analysis of the sensitivity of the mineralogical model to zeta potential showed that the dynamic modulus increases with the positive zeta-potentials and decreases with the negative zeta-potentials. The analysis of the sensitivity of the mineralogical model to the silica showed that the dynamic modulus decreases with the increase of the silica.
{"title":"Development of a Dynamic Modulus Prediction Model for Hot Mixture Asphalt and Study of the Impact of Aggregate Type and Its Electrochemical Properties","authors":"Mouhamed Lamine Chérif Aidara, Makhaly Bâ, A. Carter","doi":"10.4236/ojce.2020.103018","DOIUrl":"https://doi.org/10.4236/ojce.2020.103018","url":null,"abstract":"The most famous model known in prediction of dynamic modulus for asphalt concretes is the Witczak and Hirsh models. \u0000These models didn’t use the mineralogical and chemical properties of aggregates. \u0000Witczak models used the passing or refusal percentage to sieve diameters and Hirsh \u0000model used the volumetric \u0000analysis. All models developed until now considered that the aggregates were geotechnical \u0000conforming to standards. In this study the first mineralogical and chemical properties \u0000were considered through the percentage of silica in the rock source of aggregates \u0000and the electric aggregate particles charge zeta. Dynamic modulus values used for \u0000regression process are determined from complex modulus test on nine asphalt concretes \u0000mix designed with aggregate types (basalt of Diack, quartzite of Bakel and Limestone \u0000of Bandia). Between Twelve initial inputs, the statistical regression by exclusion process keeps only seven parameters \u0000as input for the model. The mineralogical model showed good accuracy with R2 equal to 0.09. The student test on the model parameters showed that all the parameters \u0000included in the model were meaningful with good p inferior to 0.05. The Fisher test \u0000on the model showed the same result. The analysis of the sensitivity of the mineralogical \u0000model to zeta potential showed that the dynamic modulus increases with the positive zeta-potentials and decreases with the negative zeta-potentials. The analysis \u0000of the sensitivity of the mineralogical model to the silica showed that the dynamic \u0000modulus decreases with the increase of the silica.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"204 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115727881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-22DOI: 10.4236/ojce.2020.103017
Mouhamed Lamine Chérif Aidara, Makhaly Bâ, A. Carter
Pavement design tools are not universal. Indeed, in the sizing of pavements in the USA, the prediction models used in the calculation of the dynamic modulus of HMA are not adapted to the characterization of the mineral skeleton of the HMA mix designed with the French method. This article aims to assess the predictive models of the dynamic modulus used in the mechanistic-empirical design for their use in the design of bituminous pavements, and to develop new predictive models taking into account the sieve series LC and AFNOR standards. A total of six types of mixtures were subjected to the determination of complex modulus testing by direct tensile-compression on cylindrical specimens (26-700 LC) over a temperature range (5) and frequency (5) data. Dynamic modulus prediction models |E*| are studied Witczak model 1999 and model Witczak 2006. These models do not take into account the AFNOR or LC mesh sieve, an approach was made in relation to the US mesh sieve to replace ρ200 (0.075 mm), ρ4 (4.76 mm), ρ38 (9.5 mm) and ρ34 (19 mm) respectively by the AFNOR mesh P0.08 (0.08 mm), R5 (5 mm), R10 (10 mm) and R14 (14 mm). The result is the production of two models whose are evaluated by correlation with the values |E*| of modulus measured in the laboratory is satisfactory (R2 = 0.83 respectively R2 = 0.71 and p-value = 0.00). The optimization of these approximate models gave new models with the same frame as the original models and a better correlation with the data observed in the laboratory (respectively R2 = 0. 95 and R2 = 0.91 p-value = 0.00).
{"title":"Evaluation of Dynamic Modulus of HMA Sigmoidal Prediction Models and Optimization by Approach of U.S. Mesh Sieve by AFNOR and LC Mesh Sieve","authors":"Mouhamed Lamine Chérif Aidara, Makhaly Bâ, A. Carter","doi":"10.4236/ojce.2020.103017","DOIUrl":"https://doi.org/10.4236/ojce.2020.103017","url":null,"abstract":"Pavement design tools are not universal. Indeed, in the sizing of \u0000pavements in the USA, the prediction models used in the calculation of the \u0000dynamic modulus of HMA are not adapted to the characterization of the mineral \u0000skeleton of the HMA mix designed with the French method. This article aims to assess the \u0000predictive models of the dynamic modulus used in the mechanistic-empirical \u0000design for their use in the design of bituminous pavements, and to develop new \u0000predictive models taking into account the sieve series LC and AFNOR standards. \u0000A total of six types of mixtures were subjected to the determination of complex \u0000modulus testing by direct tensile-compression on cylindrical specimens (26-700 \u0000LC) over a temperature range (5) and frequency (5) data. Dynamic modulus \u0000prediction models |E*| are studied \u0000Witczak model 1999 and model Witczak 2006. These models do not take into \u0000account the AFNOR or LC mesh sieve, an approach was made in relation to the US \u0000mesh sieve to replace ρ200 (0.075 mm), ρ4 (4.76 mm), ρ38 (9.5 mm) and ρ34 (19 mm) respectively by \u0000the AFNOR mesh P0.08 (0.08 \u0000mm), R5 (5 mm), R10 (10 mm) and R14 (14 mm). The result is \u0000the production of two models whose are evaluated by correlation with the values \u0000|E*| of modulus measured in the laboratory is \u0000satisfactory (R2 = 0.83 \u0000respectively R2 = 0.71 and p-value = 0.00). The optimization of \u0000these approximate models gave new models with the same frame as the original \u0000models and a better correlation with the data observed in the laboratory \u0000(respectively R2 = 0. 95 \u0000and R2 = 0.91 p-value = 0.00).","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"141 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122616892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-22DOI: 10.4236/ojce.2020.103021
Luxi Lu
In recent years, the number of permanent residents in Chengdu, Sichuan Province, China has continued to grow, and the number of private cars keeps rising. A series of problems caused by difficult parking and random parking in old communities are common. This paper will take the parking problem of the old community in Yingmenkou community, Chengdu, China as an example to summarize the current situation and parking problems of the private car parking facilities in these old communities. Based on Chengdu’s current old community parking management policy, parking facility renovation and expansion policy, this paper researches and establishes a parking resource sharing model suitable for old communities. The simulation results show that this model has a small footprint and is easy to install and disassemble. It can be freely spliced and combined units according to the size of the old community and the needs of residents. It is suitable for old communities with no centralized parking lot and high parking demand by residents.
{"title":"Research and Simulation of Parking Resource Sharing Mode in Old Community—Taking Yingmenkou Community as an Example","authors":"Luxi Lu","doi":"10.4236/ojce.2020.103021","DOIUrl":"https://doi.org/10.4236/ojce.2020.103021","url":null,"abstract":"In recent years, the number of permanent residents in Chengdu, Sichuan \u0000Province, China has continued to grow, and the number of private cars keeps \u0000rising. A series of problems caused by difficult parking and random parking in \u0000old communities are common. This paper will take the parking problem of the old \u0000community in Yingmenkou community, \u0000Chengdu, China as an example to summarize the current situation and parking \u0000problems of the private car parking facilities in these old communities. Based \u0000on Chengdu’s current old community parking management policy, parking facility \u0000renovation and expansion policy, this paper researches and establishes a parking resource sharing model suitable for old communities. The \u0000simulation results show that this model has a small footprint and is easy to install \u0000and disassemble. It can be freely spliced and combined units according to the \u0000size of the old community and the needs of residents. It is suitable for old \u0000communities with no centralized parking lot and high parking demand by \u0000residents.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125707987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-22DOI: 10.4236/ojce.2020.103016
Mouhamed Lamine Chérif Aidara, Makhaly Bâ, A. Carter
Several studies show that properties of Hot Mixture Asphalt (HMA) mix design materials, aggregate gradation and volumetric properties had an influence on their resistance to rutting. However, these properties do not impact in the same way this performance. For a given aggregate type, an infinity aggregate gradation type can be observed, and for each type of HMA several types of bituminous binder can be used. This article aims to measure the evolution of resistance to rutting according to the three main classes of National Cooperative Highway Research Program (NCHRP) aggregate gradation (dense-graded, fine-graded and coarse-graded). To this end, a study was conducted on the measurement of rutting resistance for eight bituminous mixtures manufactured with two bitumen types and two types of manufacturing aggregates. The results showed that there is a priority order of these different parameters on the influence of the resistance to rutting. This highlights a competition between the properties of aggregate and type of granular skeleton. Indeed, for the same type of aggregate, asphalt binder type first impacts resistance to rutting of the HMA followed by aggregate gradation, volumetric properties of the mix and finally by the angularity of the aggregates. However, this order cannot be fixed and can depend of the intensity of each parameter.
{"title":"Impact of Intrinsic Properties of Aggregate and Volumetric Properties of Hot Mixture Asphalt (HMA) in the Influence of the Resistance to Rutting","authors":"Mouhamed Lamine Chérif Aidara, Makhaly Bâ, A. Carter","doi":"10.4236/ojce.2020.103016","DOIUrl":"https://doi.org/10.4236/ojce.2020.103016","url":null,"abstract":"Several studies show that properties of \u0000Hot Mixture Asphalt (HMA) mix design materials, aggregate gradation and \u0000volumetric properties had an influence on their resistance to rutting. However, \u0000these properties do not impact in the same way this performance. For a given \u0000aggregate type, an infinity aggregate gradation type can be \u0000observed, and for each type of HMA several types of bituminous binder can be \u0000used. This article aims to measure the evolution of resistance to rutting \u0000according to the three main classes of National Cooperative Highway Research \u0000Program (NCHRP) aggregate gradation (dense-graded, fine-graded and \u0000coarse-graded). To this end, a study was conducted on the \u0000measurement of rutting resistance for eight bituminous mixtures manufactured with \u0000two bitumen types and two \u0000types of manufacturing aggregates. The results showed that there is a priority \u0000order of these different parameters on the influence of the resistance to \u0000rutting. This highlights a competition between the properties of aggregate and \u0000type of granular skeleton. Indeed, for the same type of aggregate, asphalt \u0000binder type first impacts resistance to rutting of the HMA followed by aggregate gradation, volumetric \u0000properties of the mix and finally by the angularity of the aggregates. However, this order cannot be fixed \u0000and can depend of the intensity of each parameter.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115022558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-22DOI: 10.4236/ojce.2020.103023
Bantayehu Uba Uge, Y. Guo
Foundation pit excavation engineering is an old subject full of decision making. Yet, it still deserves further research due to the associated high failure cost and the complexity of the geological conditions and/or the surrounding existing infrastructure around it. This article overviews the risk control practice of foundation pit excavation projects in close proximity to existing disconnected piled raft. More focus is given to geotechnical aspects. The review begins with achievements to ensure excavation performance requirements, and follows to discuss the complex soil structure interaction involved among the fundamental components: the retaining wall, mat, piles, cushion, and the soil. After bringing consensus points to practicing engineers and decision makers, it then suggests possible future research directions.
{"title":"Deep Foundation Pit Excavations Adjacent to Disconnected Piled Rafts: A Review on Risk Control Practice","authors":"Bantayehu Uba Uge, Y. Guo","doi":"10.4236/ojce.2020.103023","DOIUrl":"https://doi.org/10.4236/ojce.2020.103023","url":null,"abstract":"Foundation \u0000pit excavation engineering is an old subject full of decision making. Yet, it \u0000still deserves further research due to the associated high failure cost and the \u0000complexity of the geological conditions and/or the surrounding existing \u0000infrastructure around it. This article overviews the risk control practice of \u0000foundation pit excavation projects in close proximity to existing disconnected piled raft. More focus is \u0000given to geotechnical aspects. The review begins with achievements to ensure \u0000excavation performance requirements, and \u0000follows to discuss the complex soil structure interaction involved among the fundamental components: the \u0000retaining wall, mat, piles, cushion, and the soil. After bringing consensus \u0000points to practicing engineers and decision \u0000makers, it then suggests possible future research directions.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132174383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-30DOI: 10.4236/ojce.2020.102011
Hao Luo
In order to analyze the deformation and stress characteristics of the pile foundation on the slope, this paper uses the finite element software Abaqus for numerical simulation. The displacement and stress data of pile under different working conditions (the combination of heap load and vertical load and horizontal load and inclined load) were collected; the distribution of pile displacement, axial force and bending moment were analyzed. Simulation results show that: slope top loading has little effect on vertical displacement; when the heap load exceeds 200 kPa, the horizontal displacement is greatly affected. Pile axial force decreases with pile burial depth; pile lateral resistance plays a more adequate role in the rock and soil layer. The bending moment of double pile foundation is positive at the top and negative at the bottom. Applied oblique load has obvious p-Δ effect.
{"title":"Research on Effect of Heap Loading on Deformation and Mechanical Properties of Bridge Double Pile Foundation on Steep Slope","authors":"Hao Luo","doi":"10.4236/ojce.2020.102011","DOIUrl":"https://doi.org/10.4236/ojce.2020.102011","url":null,"abstract":"In order \u0000to analyze the deformation and stress characteristics of the pile foundation on \u0000the slope, this paper uses the finite element software Abaqus for numerical \u0000simulation. The displacement and stress data of pile under different working conditions \u0000(the combination of heap load and vertical load and horizontal load and inclined \u0000load) were collected; the distribution of pile displacement, axial force and bending moment were \u0000analyzed. Simulation results show that: slope top loading has little effect on vertical \u0000displacement; when the heap load exceeds 200 kPa, the horizontal displacement is greatly \u0000affected. Pile axial force decreases with pile burial depth; pile lateral \u0000resistance plays a more adequate role in the rock and soil layer. The bending moment \u0000of double pile foundation is positive at the top and negative at the bottom. Applied oblique \u0000load has obvious p-Δ effect.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116964393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-30DOI: 10.4236/ojce.2020.102008
Lu Dong, Han-sheng Geng, Hongfa Xu, Yinhao Yang
Rocks are composed of mineral particles and micropores between mineral which has a great influence on the mechanical properties of rocks. In this paper, based on the theory of locked-in stress developed by academician Chen Zongji, the locked-in stress problem in underground rock is simulated by the thermal expansion of hard rubber particles. The pore inclusion in rock is assumed to be uniformly distributed spherical cavities. Using the thermal stress theory, the stress of rock with a spherical pore inclusion is equivalent to the thermal stress generated by the spherical hard rubber inclusion. The elastic theory formula of the temperature increment and the equivalent pore pressure of the spherical hard rubber inclusion is derived. The numerical simulation of the rock mass model with a spherical hard rubber inclusion is carried out and compared to the theoretical calculation results; the results show that they are consistent. The method proposed by this paper for simulating stress distribution in rock by thermal stress is reasonable and feasible; it has a positive meaning for further study of mechanic phenomenon of rock with micropore inclusion.
{"title":"Theoretical Analysis of Simulating the Locked-In Stress in Rock Pore by Thermal Expansion of Hard Rubber","authors":"Lu Dong, Han-sheng Geng, Hongfa Xu, Yinhao Yang","doi":"10.4236/ojce.2020.102008","DOIUrl":"https://doi.org/10.4236/ojce.2020.102008","url":null,"abstract":"Rocks are composed of mineral particles and micropores between mineral which has a great influence on the mechanical properties of rocks. In this paper, based on the theory of locked-in stress developed by academician Chen Zongji, the locked-in stress problem in underground rock is simulated by the thermal expansion of hard rubber particles. The pore inclusion in rock is assumed to be uniformly distributed spherical cavities. Using the thermal stress theory, the stress of rock with a spherical pore inclusion is equivalent to the thermal stress generated by the spherical hard rubber inclusion. The elastic theory formula of the temperature increment and the equivalent pore pressure of the spherical hard rubber inclusion is derived. The numerical simulation of the rock mass model with a spherical hard rubber inclusion is carried out and compared to the theoretical calculation results; the results show that they are consistent. The method proposed by this paper for simulating stress distribution in rock by thermal stress is reasonable and feasible; it has a positive meaning for further study of mechanic phenomenon of rock with micropore inclusion.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117076352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-27DOI: 10.4236/ojce.2020.102014
A. Suzuki, Tomomi Fujita, Y. Kimura
On the 2011 off the Pacific Coast of Tohoku Earthquake, gymnasium buildings exhibited the unexpected structural damages, which prevented a use as evacuation shelters in during- and post-disaster periods. The major failure occurring on the connection between the RC column top and steel roof as well as the cracks in the RC column base was observed during the emergent inspection. According to the earlier studies, it was implied that the presence of the slotted hole possibly deteriorates the seismic capacity; however, the length of slotted hole was fixed at a certain value. Facing this concern, this research attempts to clarify the influence of the slotted hole length through a comprehensive parametric study by pushover and seismic response analyses. In conclusion, it has been discovered that the slotted hole deteriorates the seismic capacity for the connection failure up to almost 50% of that without slotted hole. Moreover, the discrepancy of characteristics obtained by the static and dynamic analyses is originated by means of the presence of slotted hole. This slotted hole effect should be noted by structural engineers and researchers to provide the adequate seismic diagnosis and strengthening.
{"title":"Slotted Hole Effect on Damage Mechanism of Gymnasium Building with RC Frame and Steel Roof","authors":"A. Suzuki, Tomomi Fujita, Y. Kimura","doi":"10.4236/ojce.2020.102014","DOIUrl":"https://doi.org/10.4236/ojce.2020.102014","url":null,"abstract":"On the \u00002011 off the Pacific Coast of Tohoku Earthquake, gymnasium buildings exhibited \u0000the unexpected structural damages, which prevented a use as evacuation shelters \u0000in during- and post-disaster periods. The major failure occurring on the connection between the RC column top and steel roof as well as \u0000the cracks in the RC column base was observed \u0000during the emergent inspection. According to the earlier studies, it was \u0000implied that the presence of the slotted hole possibly deteriorates the seismic \u0000capacity; however, the length of slotted hole was fixed at a certain value. \u0000Facing this concern, this research attempts to clarify the influence of the \u0000slotted hole length through a comprehensive parametric study by pushover and \u0000seismic response analyses. In conclusion, it has been discovered that the \u0000slotted hole deteriorates the seismic capacity for the connection failure up to \u0000almost 50% of that without slotted hole. Moreover, the discrepancy of \u0000characteristics obtained by the static and dynamic analyses is originated by \u0000means of the presence of slotted hole. This slotted hole effect should be noted \u0000by structural engineers and researchers to provide the adequate seismic \u0000diagnosis and strengthening.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123692737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-27DOI: 10.4236/ojce.2020.102010
T. Johnarry, Francis Williams Ebitei
The pure shear strength for the all-simply supported plate has not yet been found; what is described as pure shear in that plate, is, in fact, a pure-shear solution for another plate clamped on the “Y-Y” and simply supported on the long side, X-X. A new solution for the simply supported case is presented here and is found to be only 60-percent of the currently believed results. Comparative results are presented for the all-clamped plate which exhibits great accuracy. The von Misses yield relation is adopted and through incremental deflection-rating the effective shear curvature is targeted in aspect-ratios. For a set of boundary conditions the Kirchhoff’s plate capacity is finite and invariant for bending, buckling in axial and pure-shear and in vibration.
{"title":"Von Misses Pure Shear in Kirchhoff’s Plate Buckling","authors":"T. Johnarry, Francis Williams Ebitei","doi":"10.4236/ojce.2020.102010","DOIUrl":"https://doi.org/10.4236/ojce.2020.102010","url":null,"abstract":"The pure \u0000shear strength for the all-simply supported plate has not yet been found; what is \u0000described as pure shear in that plate, is, in fact, a \u0000pure-shear solution for another plate clamped on the “Y-Y” and simply supported \u0000on the long side, X-X. A new solution for the simply supported case is \u0000presented here and is found to be only 60-percent of the currently believed \u0000results. Comparative results are presented for the all-clamped plate which \u0000exhibits great accuracy. The von Misses yield relation is adopted and through \u0000incremental deflection-rating the effective shear curvature is targeted in \u0000aspect-ratios. For a set of boundary conditions the Kirchhoff’s plate capacity \u0000is finite and invariant for bending, buckling in axial and pure-shear and in \u0000vibration.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126849806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-27DOI: 10.4236/ojce.2020.102009
Isah Funtua Abdulkadir, H. M. Alhasssan
The present work investigated the properties of the commonly used Butimen for road construction in Nigeria (60/70 pen.) for normal temperature and climate Effect. The laboratory tests conducted were penetration, softening point, viscosity, ductility test and flash and fire point test based on the ASTM standards. The result indicates a decrease in stiffness of bitumen with an increase in temperature, with a decrease in penetration of bitumen by 85.5% when tested between 25°C to 43.2°C and also the Ductility decreases with increase in temperature by 54.9% between 25°C and 43.2°C. The viscosity result shows a decrease in viscosity with an increase in temperature, therefore at higher temperature Bitumen is likely to flow.
{"title":"Impact of Climate Change on Rheological Properties of Bitumen","authors":"Isah Funtua Abdulkadir, H. M. Alhasssan","doi":"10.4236/ojce.2020.102009","DOIUrl":"https://doi.org/10.4236/ojce.2020.102009","url":null,"abstract":"The present work investigated the properties of the \u0000commonly used Butimen for road construction \u0000in Nigeria (60/70 pen.) for normal temperature and climate Effect. The \u0000laboratory tests conducted were penetration, softening point, viscosity, \u0000ductility test and flash and fire point \u0000test based on the ASTM standards. The result indicates a decrease in stiffness \u0000of bitumen with an increase in \u0000temperature, with a decrease in \u0000penetration of bitumen by 85.5% when tested between 25°C to 43.2°C and also the \u0000Ductility decreases with increase in temperature by 54.9% between 25°C and \u000043.2°C. The viscosity result shows a decrease in viscosity with an increase in temperature, therefore at higher temperature Bitumen is likely to flow.","PeriodicalId":302856,"journal":{"name":"Open Journal of Civil Engineering","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125852555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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